MSI_000033159

Pyridoxal is a pyridinecarbaldehyde that is pyridine-4-carbaldehyde bearing methyl, hydroxy and hydroxymethyl substituents at positions 2, 3 and 5 respectively. Pyridoxal, also known as pyridoxaldehyde, belongs to the class of organic compounds known as pyridoxals and derivatives. Pyridoxals and derivatives are compounds containing a pyridoxal moiety, which consists of a pyridine ring substituted at positions 2, 3, 4, and 5 by a methyl group, a hydroxyl group, a carbaldehyde group, and a hydroxymethyl group, respectively. Pyridoxal is one form of vitamin B6. Pyridoxal exists in all living species, ranging from bacteria to humans. In humans, pyridoxal is involved in glycine and serine metabolism. Pyridoxal has been detected, but not quantified in several different foods, such as sourdoughs, lichee, arctic blackberries, watercress, and cottonseeds. Some medically relevant bacteria, such as those in the genera Granulicatella and Abiotrophia, require pyridoxal for growth. This nutritional requirement can lead to the culture phenomenon of satellite growth. In in vitro culture, these pyridoxal-dependent bacteria may only grow in areas surrounding colonies of bacteria from other genera ("satellitism") that are capable of producing pyridoxal. Pridoxal has a role as a cofactor, a human metabolite, a Saccharomyces cerevisiae metabolite, an Escherichia coli metabolite and a mouse metabolite.